1. Field of the Invention
This invention relates to drive axle assemblies, and, in particular, to a drive axle assembly having an improved structure for the output shaft and supporting bearings.
2. Discussion of Related Art
A conventional tandem drive axle assembly includes forward and rear drive axle assemblies and an intermediate drive shaft extending between the forward and rear drive axle assemblies. An inter-axle differential housed in one of the drive axle assemblies, typically the forward drive axle assembly, transfers power from the vehicle drive shaft and divides that power between forward and rear axles. The inter-axle differential transfers power to the rear drive axle assembly through an output shaft extending from the forward axle assembly and coupled to the intermediate drive shaft assembly.
In conventional drive axle assemblies, the output shaft described above is coupled to the intermediate drive shaft assembly through a yoke. The yoke is coupled to the output shaft through a spline connection and a nut retains the yoke on the end of the output shaft. The output shaft is supported for rotation within a housing of the forward drive axle assembly by inner and outer tapered roller bearings in endplay or a ball bearing. Conventional drive axle assemblies employing this arrangement have several disadvantages. The drive shaft requires two separate parts and is relatively costly and heavy and requires the use of a nut to retain the yoke on the shaft.
The inventors herein have recognized a need for a tandem axle assembly that will minimize and/or eliminate one or more of the above-identified deficiencies.